Safety guard for rotary power tool



Mardl 1957 J. B. LUTTON 2,785,716

SAFETY GUARD FOR ROTARY POWER TOOL Filed July 6. 1955 FIG 3 14 g i 1: 68INVENTOR J \\\5! JOSEPH B. LUTTON 22, av g ATTORNEY United States Fatent@fiice Patented Mar. 1 3, 1957 SAFETY GUARD FUR ROTARY POWER TOOL JosephB. Lutton, Lancaster, Pa., assignor to De Wait Inc., a corporation ofPennsylvania Application July 6, 1955, Serial No. 529,193

4 Claims. (Cl. 144-251) This invention relates to safety guards forpower tools, and more particularly to a safety guard for a rotaryshaping tool secured to a rotating vertical shaft.

It is the purpose of this invention to provide a simple and readilyadjustable means for guarding a rotary cutting tool during the cuttingoperation to prevent injury to the operator.

Heretofore, to my knowledge, no satisfactory guard has been devised forprotecting the operator when a power tool is used for shaping. Varioustypes of tool guards have been devised for use when the power tool has acircular saw mounted thereon but such guards must be removed or movedinto inoperative position when a shaping tool is employed or morespecifically when the motor or drive shaft are in a vertical position asin the operation of shaping. It is therefore an obiect of my inventionto design a simple but eifective guard to prevent inadvertent injuryduring this type of operation.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My inventionitself, however, both as to its organization and method of operation maybe undersiood by reference to the structure embodying my invention andshown in the accompanying drawings in which I illustrate:

Fig. 1 shows a plan view of the safety guard mounted on the motorhousing;

Fig. 2 is a perspective front elevation of the device, and

Fig. 3 is a sectional elevation taken on the line 3-3 of Fig. l.

The motor 16 has a housing 12 having an annular extension 14 in which isformed an annular groove 16. The extended arbor shaft 1'? of the motorll protrudes through the center of extension 14. Arbor shaft 1? has ashoulder 19 and is threaded at its end to receive nut 20. Collar 18 anda shaping tool 22 are detachably secured to the shaft between shoulder19 and nut Shaping tool 22 carries the cutting bits 23.

A semi-circular bracket 24 has a flange 2-5 shaped to engage the annulargroove 16 as shown in Figs. 1 and 3. Bracket 24 is secured in thisposition by a threaded stud 26 extending from motor housing 12 through aslot in annular bracket 24. Wing nut 28 draws the bracket 24 tight onstud 26 for tight fitting engagement of the bracket in annular groove16.

An arcuate skirt-like guard 32 is slidably supported on a pair ofupstanding pins 39 secured to bracket 24. Set screws 34 hold guard 32 inadjusted position on the pins 36. As shown, the pins 30 are spaced about100 degrees from each other to provide adequate support for guard 32.

In operation, the workpiece 36 is supported on the table 38 and theguard 32 is lowered almost to the workpiece as shown in Fig. 3,whereupon the set screws 34 are secured. The height of the pins 30provides a range of adjustment for various sizes of workpieces 36. Theworkpiece 36 may then be guided along a conventional fence (not shown)and into engagement with the cutting bits 23 of shaping tool 22.

It will be evident that the operator who is holding the workpiece 36 ispositively prevented from inadvertently inserting his fingers into thecutting tool during the shaping operation. A simple adjustment of theguard 32 up and down along the pins 39 accommodates the various sizedworkpieces 36.

I claim:

1. A safety guard suitable for attachment to a rotary power tool havinga motor and protruding arbor shaft positioned above a work supportingtable, an arcuate bracket securable to the housing of said motor,upstanding pins on said bracket, an arcuate skirt-shaped guard slidablymounted on said pins, and means to secure said guard against movementalong said pins whereby said guard may be adjusted to a position abovethe workpiece and with said bracket and said workpiece enclosing acutting tool on said arbor shaft.

2. In combination, a machine having a rotary cutting tool positioned ona vertical axis adapted to engage a workpiece by relative movementbetween said cutting tool and said workpiece, a horizontal arcuatebracket secured against rotation above said rotary cutting tool andconcentric thereto, upstanding pins adjacent the edge of said arcuatebracket, a skirt-like arcuate guard slidably secured on said pins forvertical adjustment, said skirt-like guard having a greater are than thearc of said cutting tool and being positioned concentric thereto on saidarcuate bracket, and means to secure said skirtlike guard in adjustedvertical elevation on said upstanding pins whereby said skirt-like guardmay be adjusted down to a workpiece to form therewith a guard about saidtool.

3. In combination, a machine having a rotating shaft, a stationaryhousing concentric about a portion of said rotating shaft, a cuttingtool on said rotating shaft, said shaft being in substantially verticalposition and said cutting tool rotating in a substantially horizontalplane, an arcuate bracket securable to said housing and concentric tosaid shaft, vertical pins secured to said bracket, an arcuate skirtslidably supported on said pins for vertical adjustment, said arcuateskirt having an arc of greater radius than the radius of said cuttingtool, and means to secure said arcuate skirt in an adiusted positionslightly above a workpiece, said arcuate skirt said bracket and saidworkpiece forming a protective guard about the top and side of saidcutting tool.

4. A safety device suitable for positioning about a rotating shafthaving a cutting tool thereton, said device comprising an arcuatestationary bracket to be positioned concentrically about said shaft in aplane transverse thereto, upstanding pins on said bracket, said pinsbeing substantially parallel to said rotating shaft, and an arcuateskirt-like guard slidably mounted on said pins and having a skirt-likearcuate wall substantially concentric to said shaft, said guard formingwith said bracket a protective guard about a portion of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS1,598,498 Paden Aug. 31, 1926 1,715,292 Hoffman et al May 28, 19291,807,561 White May 26, 1931 FOREIGN PATENTS 13,858 Great Britain of1898 142,431 Germany July 13, 1903 191,600 Great Britain Ian. 18, 1923

